<b>Incidence of type 2 diabetes with verapamil compared with other calcium channel blockers</b>

<p dir="ltr">Objective. Evidence that the calcium channel blocker (CCB) verapamil slows type 1 diabetes progression suggests possible preventive benefits among people at risk of type 2 diabetes. We compared type 2 diabetes incidence between users of verapamil vs. other CCBs in a population-based cohort.</p><p dir="ltr">Research Design and Methods. From a random sample of Australians in national subsidized healthcare databases, we identified 90026 individuals who initiated treatment with a CCB (≥2 supplies) between July-2003 and December-2014. Incident diabetes was captured by subsequent receipt of glucose-lowering treatment or registration on the National Diabetes Services Scheme. Individuals were followed from first CCB supply until discontinuation, diabetes onset, death, or end-2014. Multi-state Poisson regression models characterised associations of CCB subclass with type 2 diabetes incidence and death (competing event), after multivariable propensity score adjustment.</p><p dir="ltr">Results. The cohort comprised 4485 verapamil users (5.0%) and 85541 treated with other CCBs (mostly dihydropyridines). During a median 1.6-year follow-up, 101 verapamil-treated individuals developed type 2 diabetes (8.8 per 1000 person-years) compared with 2622 people treated with other CCBs (11.4 per 1000 person-years). This translated to an incidence rate ratio of 0.77 (95% CI 0.63 to 0.94) in favor of verapamil (fully adjusted), and a lower probability of type 2 diabetes at 6 years (4.2% [95% CI 3.3%–5.3%] vs. 5.4% [4.7%–6.3%] for a typical clinical profile; absolute risk difference: 1.3% [95% CI –0.1%–2.4%]). Results were robust across multiple sensitivity analyses.</p><p dir="ltr">Conclusions. Verapamil use is associated with a lower incidence of type 2 diabetes compared with other CCBs. </p><p><br></p>